Hey korora, I hear you. I've heard this now from a few others and I've experienced it myself. They do clean up decently, but it's also a hassle to even have to bother with cleaning them so I get that, too.

When I went to work on having these cases produced, I chose the TPU b/c I was worried about how a hard plastic case might scratch up some of my designs - in particular any that have a mirror polish to them. I hadn't even considered that they could fog up or possibly yellow over time. Besides protecting the finishes of the bars, I also preferred the idea of the TPU b/c I believed it would protect the bars significantly more when anyone decided to ship these anywhere - they'd have a nice soft cushion as opposed to a hard, plastic one.

I would like to dig int this more, and to have a conversation with my suppliers on other potential options. I also want to be careful here... function over form might be the best path forward considering that a kialara if damaged cannot be repaired as these are sealed permanently with the screws set in with loctite.

Perhaps this issue with the cases is something I can begin to look into more seriously next year. And also, to answer your question, the leather cases are designed to hold these bars inside of their TPU cases... again, placing priority on protecting the pieces.

Thank you for reaching out and sharing.

And MJ thaks for chiming in here as well!!